Environmental control unit drain means

ABSTRACT

A vehicle includes a cab which houses an environmental control unit. The control unit includes a housing in which is mounted the usual environmental control components including a blower fan, a heater and evaporator core means, and a filter. Located so as to collect condensate from the heater and evaporator core means is a compartment defined by the housing. A pair of drain tubes are each reversely bent between upper and lower open ends, the upper ends being in fluid communication with the bottom of the compartment and the lower ends being open to the atmosphere.

V O United States Patent 1191 [11] 3,918,271

Whisler 5] Nov. 11, 1975 [5 ENViRONMENTAL CONTROL UNIT DRAIN 3.199.307 8/1965 Willis 62/291 MEANS 3.626713 12/1971 Venable 62/187 [75] Inventor: Edwin Lee Whisler, Peosta, lowa Primary E aml-ner wmiam J Wye [73] Assignee: Deere & Company, Moline, 1]]. 22 Filed: Aug. 19, 197 [571 ASSTRACT A vehicle includes a cab which houses an environmen- [21] Appl. No.: 498,252 tal control unit. The control unit includes a housing in which is mounted the usual environmental control [52] US. Cl. 62/285; 62/239; 62/289; Components including a blower a heater and 62/291; 165/41 evaporator core means, and a filter. Located so as to 51 rm. cl. F25D 21/14 collect condensate from the heater and evaporator [58] Field or Search 62/289, 291, 285, 239; core means is a Compartment defined y the g- 165/41 A pair of drain tubes are each reversely bent between 1 upper and lower open ends, the upper ends being in [56] References Cit d fluid communication with the bottom of the compart- UNITED STATES PATENTS ment and the lower ends being open to the atmo- 2.430,335 11/1947 Hart 62/244 Sphere 2.532.618 12/1950 Henney 62/323 3 Claims, 3 Drawing Figures U.S. Patent Nov. 11, 1975 lllllllllllllllll A l l l l l l l l n l 1 ENVIRONMENTAL CONTROL UNIT DRAIN "MEANS BACKGROUND OF THE INVENTION The present invention relates to an environmental control unit and more particularly relates to means for draining condensate from such a unit. a

Some of the problems attendant with draining condensate from an environmental-control unit are set forth in US. Pat. No; 3,626,713 issu ed on Dec. l4, 1971 to Venable.'The present inventionrepresents an alternate solution to these problems. 1 k

Specifically, in Venable a condensate zdrain tube is provided with an extremely flexible lower end which collapses in response to a vacuum condition-in the housing of theenvironmental control unit to prevent outside air from passing through the'tube to the housing. Because of its extremely flexible nature, the durability of the tube lower end is somewhat .in doubt. Furthermore, it is feared that the tube lower end may take a collapsed set which would "hamper or prevent draining.

Additionally, prior art environmental units have'the condensation collection trays thereof located in the path of air flow to their evaporator cores. This requires the trays to be made quite shallow so that they will not interfer with the air flow and the head of water collected in the tray is sometimes not enough to overcome the vacuum condition in the unit housing thus resulting in the condensate spilling before it drains.

SUMMARY OF THE INVENTION According to the present invention there is provided a novel drain means for draining condensate from a vehicle environmental control unit.

An object of the invention is to provide a drain means which is simple, effective and durable.

More specifically, it is an object to provide a drain means including a drain tube which is reversely bent between its upper and lower ends so as to'trap condensate so that the latter will act to prevent outside air from passing through the tube to the interior of the housing of the environmental control unit.

A further object is to provide a bracket for maintaining the tube in its reversely bent shape.

Still another object is to make the tube of material which is sufficiently flexible to withstand expansion and contraction as may be induced by the freezing and thawing of trapped condensate during cold weather.

Yet another object is to arrange the components of the environmental control unit such that the condensate collection compartment is not positioned in the path of air flow to the evaporation core thus permitting the compartment to be relatively deep to ensure collection of a head of water sufficient to effect positive draining of the condensate.

These and other objects will be apparent from a reading of the following description in conjunction with the appended drawing.

BRIEF DESCRIPTION OF THE DRAWING environmental control unit of the vehicle.

FIG. 3 is'a sectional view taken along the line 3-3 of FIG. 2, but showing only a portion of thecontrol unit.

1 DESCRIPTION OF THE PREFERRED r EMBODIMENT Referring now to the drawing, there is shown an industrial vehicle indicated in itsentiretyby the reference numeral 10. The vehicle 10 is an articulated type having front and rear main frame sections 12 and 14 respectively mounted'on front and rear pairs of drive wheels 16 and 18 and interconnected by a vertical pivot assembly, shown generally at 20.

.Mounted on the front'frame section 12 adjacent the pivotas sembly 20 is a boom structure includinga base or lower boorn section 22'mounted1in a conventional manner (not shown) for slewing about a vertical axis. Theboom section 22 includes an elevated portion 24 which is offset from the axis of movement of the boom sectionso as to trace a' horizontal path which passes above the vertical pivot assembly 20. Further boom sections (not shown) would normally be supported on the base. section 22 and would serve'to support an implement such as a treeshearhead or grapple or the like.

Supported on the rear end oftherear frame section 14 is a radiator and fan housing 26 having a hood 28 extending forwardly therefrom and defining the top of an engine compartment, as is conventional. A cab 30 is mounted on the frame section 14 between the engine compartment and the pivot assembly 20. The cab 30 includes a lower forward portion 32 which projects forwardly above the pivot assembly 20 and terminates in a louvered front wall 34.

Positioned in the forward portion 32 of the cab 30 is an environmental control unit 33 including a box-like frame or housing 36 mounted from supports 38 of the rear frame 14 through means of a plurality of resilient mounts 40 which act to isolate the unit 34 from vibrations induced in the frame section 14 during operation of the vehicle 10.

Mounted in the housing 36 of the unit 34 in serial order from front to the rear thereof are a filter 42, heater and evaporator coils or core 44 and a blower fan 46, all being shown schematically.

The housing 36 has upper and lower parallel walls 50 and 52 which are inclined upwardly towards the rear of the vehicle and the lower wall 52 serves to direct condensate, falling as droplets from the evaporator coils 44, to a compartment 54 arranged just forwardly and below the cooling coils so as to not interfere with the flow of air passing into the housing 36 through an opening 55 in the forward end thereof from the louvered front wall of the cab.

A pair of identical, reversely bent drain tubes 56 (only the right one is shown) have respective upper ends mounted in the bottom of the compartment 54 and respective lower ends projecting downwardly through a bottom wall 58 of the cab portion 32 which is inclined downwardly and rearwardly from the louvered front wall 34. The reverse bend of each drain tube 56 is maintained by a U-shaped bracket 60 fixed to a horizontal bottom wall 62 of the housing 36, a part of the wall 62 defining the bottom of the compartment 54. The reverse bend of each tube 56 serves to collect water so as to form a barrier for preventing air from being drawn thereinto due to a vacuum condition normally induced in the housing 36 due to the operation of the blower 46 and the filter 42. Since the compartment 54 is arranged so as not to interfere with the movement of air through the evaporator core, it is made deep enough to collect a head of water sufficient to force water out the drain tube before it spills from the compartment. The wall of each tube 56 is preferably quite thin so as to easily expand and contract when the water trapped thereby freezes and thaws during operation of the vehicle in cold weather.

The operation of the invention is thought to be obvious from the foregoing description and for the sake of brevity a discussion of the operation is omitted.

I claim:

1. In a vehicle cab including an air conditioning system and being of a type including an operators enclosure, an environmental control unit including a housing contiguous with the enclosure and having outlet passage means opening thereinto and having inlet passage means located for allowing outside air to pass into the housing, a blower fan located in the housing for drawing air in said inlet passage means and for forcing air out said outlet passage means, an evaporator means located in the housing between the blower and inlet passage means, a filter located in the housing between the inlet passage means and the evaporator means, a compartment located below said evaporator means for collecting condensation and a drain tube having an upper end connected in fluid communication with the bottom of the compartment and having a lower end positioned exteriorly of the housing at a level below the compartment, the improvement comprising: said drain tube being reversely bent between its upper and lower ends and held in place by a bracket means fixed to the exterior of the housing whereby a column of condensate will accumulate in the drain tube so as to prevent air from being drawn therethrough due to any vacuum condition which might occur in the housing due to the operation of the blower fan and filter.

2. The vehicle cab defined in claim 1 wherein said bracket means comprises a U-shaped member having opposite legs secured to the housing and having at least three substantially vertical apertures located in a connecting portion joining the legs; and said drain tube being received in the apertures so as to form a trap between the upper and lower ends thereof.

3. The vehicle cab defined in claim 1 wherein the walls of the drain tube are sufficiently thin so as to easily expand and contract in the event that said column of condensate freezes and thaws in the tube. 

1. In a vehicle cab including an air conditioning system and being of a type including an operators enclosure, an environmental control unit including a housing contiguous with the enclosure and having outlet passage means opening thereinto and having inlet passage means located for allowing outside air to pass into the housing, a blower fan located in the housing for drawing air in said inlet passage means and for forcing air out said outlet passage means, an evaporator means located in the housing between the blower and inlet passage means, a filter located in the housing between the inlet passage means and the evaporator means, a compartment located below said evaporator means for collecting condensation and a drain tube having an upper end connected in fluid communication with the bottom of the compartment and having a lower end positioned exteriorly of the housing at a level below the compartment, the improvement comprising: said drain tube being reversely bent between its upper and lower ends and held in place by a bracket means fixed to the exterior of the housing whereby a column of condensate will accumulate in the drain tube so as to prevent air from being drawn therethrough due to any vacuum condition which might occur in the housing due to the operation of the blower fan and filter.
 2. The vehicle cab defined in claim 1 wherein said bracket means comprises a U-shaped member having opposite legs secured to the housing and having at least three substantially vertical apertures located in a connecting portion joining the legs; and said drain tube being received in the apertures so as to form a trap between the upper and lower ends thereof.
 3. The vehicle cab defined in claim 1 wherein the walls of the drain tube are sufficiently thin so as to easily expand and contract in the event that said column of condensate freezes and thaws in the tube. 